Feed compositon for fowls

ABSTRACT

A feed composition for fowls containing casein phosphopeptide. 
     The feed compositon increases calcium intake of fowls, and when it is fed to chicks it brings increase in bone growth and body weight, low feed requirement and high breeding efficiency. When it is fed to adult chickens for egg production in a later stage, egg breakage is decreased by little decrease of eggshell strength.

This application is a continuation of application Ser. No. 348,286,filed May 5, 1989 now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a feed composition for fowls which improvescalcium intake, bone formation and eggshell quality.

2. Description of the Prior Art

Feed compositions for fowls contain a protein source, an energy source,a calcium source, a phosphorus source, vitamins, minerals and the like.The protein is fish meal, soybean cake, rapeseed cake, feather meal,meat bone meal or the like, and as the calcium source, calcium carbonateis blended in a form of shell powder.

Recently, breeding space per one fowl gradually decreased according tothe scale expansion and intensiveness in fowl breeding, and as a result,the motion quantity of the fowls gradually decreased. Besides, the fowlswere not bred under natural light, and therefore, the breedingcircumstances became worse for the bone growth of the fowls. Moreover,in the case of adult chicken for the production of eggs, there is aproblem in eggshell quality. In general, eggshell quality of adultchicken for the production of eggs becomes worse after 400 days old.Eggshell also becomes worse in summer season by a high temperaturestress. In order to improve the formation of bone and eggshell,commercial feeds usually contain a sufficient amount of the nutrientsnecessary for forming bone and eggshell such as a calcium source, aphosphorus source, various vitamins and minerals. However, when theblending amounts of these nutrients are increased, there is a limit tothe improvement in bone and eggshell formation. Therefore, it is desiredto develop another means of increasing calcium intake and improving theformation of bone and eggshell.

SUMMARY OF THE INVENTION

An object of the invention is to provide a feed composition capable ofincreasing calcium intake of a fowl.

Another object of the invention is to provide a feed composition forchick excellent in bone growth, increase of body weight, low feedrequirement and high breeding efficiency.

Another object of the invention is to provide a feed composition foradult chicken for the production of eggs capable of decreasing brokenegg, increasing eggshell strength and elongating the exchanging cycle ofthe adult chicken.

The present inventors investigated in order to achieve such objects, andfound that, when casein phosphopeptide is added to a feed compositionfor fowl, calcium intake increases and the formations of bone andeggshell are promoted. Thus, the present invention provides a feedcomposition for fowls to which casein phosphopeptide is blended.

DETAILED DESCRIPTION OF THE INVENTION

The casein phosphopeptide is a hydrolyzate of casein, and it is aphosphopeptide having an active site to bind to calcium. There are threekinds of casein, i.e., α-casein, β-casein and γ-casein, and every onemay be used for the feed composition of the invention. With respect tocasein phosphopeptide, there are some reports, and it has beenelucidated that the hydrolyzate of α-casein decomposed with trypsin isthe peptide chain portion of Asp⁴³ -Lys⁷⁹, and the hydrolyzate ofβ-casein decomposed with trypsin is the peptide chain portion ofN-terminal-Arg²⁵. However, the casein phosphopeptide may be any otherone having an active site to bind to calcium and a molecular weightbeing absorbable from the intestinal tract of a fowl. The active site tobind to calcium is now considered the portion of ##STR1## and themolecular weight may be less than about 10,000. The decomposition methodfor producing casein phosphopeptide is not restricted, however,preferable methods use a protease not decomposing the active site, suchas pepsin or trypsin. The content of the casein phosphopeptide is about0.01 to 3 wt. %, and about 0.01 to 1 wt. % is preferred.

The other components of the feed composition may be the same as a knownfeed for fowls, and include a protein source, an energy source, acalcium source, a phosphorus source, vitamins, minerals and the like.The protein source is fish meal, soybean cake, rapeseed cake, feathermeal, meat bone meal or the like, and amino acids such as DL-methionine,L-tryptophan, L-lysine or L-threonine may be added for the complement ofamino acid imbalance. As the energy source, there are carbohydrates,such as corn, milo and wheat flour, and fats, such as fat for feed,soybean oil and powder fat. As the calcium source, there is calciumcarbonate. The feed composition contains about 12 to 25% of crudeprotein, about 3 to 10% of crude fats, about 1 to 4.5% of calcium andabout 2,700 to 3,300 kcal/kg of ME.

The feed composition of the invention may be manufactured according to aconventional process, and the casein phosphopeptide may be blendedtogether with other feed components, or blended separately.

The feeding method of the feed composition to fowl may also beconventional. The fowls suitable for the feed composition of theinvention are chicks of 0 day old to 10 weeks old.

EXAMPLES Example 1

Casein was dissolved in water in a concentration of 20 w/w %, and 0.05%of crystal trypsin as a ratio to the solid weight of the casein wasadded. The mixture was allowed to react at 50° C. at pH 7.0 for 2 hours,and then the enzyme was inactivated. The reaction mixture wasconcentrated, and dried by spray drying to obtain casein phosphopeptide.

A commercial prestarter feed of egg-type chicks ("CI Pre-starter", tradename, C. Itoh Feed Mills Co., Ltd.) was blended with 0.3 wt. %, 1.0 wt.% or 3.0 wt. % of the casein phosphopeptide ("CPP", trade name MeijiSeika Kaisha, Ltd.) to prepare three kinds of the feed containing CPP.For comparison, the same amount of casein was blended to the samecommercial feed instead of CPP to prepare also three kinds of the feeds.

210 chicks of 0 day old were divided into 21 groups each composed of 10chicks, and 7 test sections each composed of three groups were prepared.Each test section was fed with one of the above 6 kind feeds or theoriginal commercial feed not blended with CPP nor casein, and bred for10 days.

The breeding results are summarized in Table 1.

                                      TABLE 1                                     __________________________________________________________________________    CPP      Casein                                                                             Breeding Result                                                     Content                                                                            Content                                                                            Increase of                                                                            Feed   Thigh Bone                                                                          Ca Content of                             Section                                                                           (%)  (%)  Body Weight (g)                                                                        Requirement                                                                          Weight (g)                                                                          Thigh Bone (%)                            __________________________________________________________________________    1   --   --   64.1     1.623  0.576 5.18                                      2   0.3  --   69.5     1.538  0.636 5.62                                      3   1.0  --   69.6     1.530  0.597 5.61                                      4   3.0  --   66.8     1.612  0.583 5.66                                      5   --   0.3  60.2     1.747  0.537 5.26                                      6   --   1.0  62.9     1.612  0.604 5.46                                      7   --   3.0  63.8     1.619  0.560 5.28                                      __________________________________________________________________________

Example 2

A commercial starter feed of egg-type chicks ("CI Starter A", tradename, C. Itoh Feed Mills Co., Ltd.) was blended with CPP so as to become0.3 wt. %.

150 chicks of 7 days old were divided into 2 groups each composed of 75chicks. One group was fed with the above feed blended with CPP, and theother group was fed with the original commercial feed not blended withCPP. Both groups were bred for two weeks up to 21 days old.

The breeding results are summarized in Table 2.

                  TABLE 2                                                         ______________________________________                                                           Increase of                                                                             Feed   Length of                                       Test         Body      Require-                                                                             Crural Bone                               Group Conditions   Weight (g)                                                                              ment   (mm)                                      ______________________________________                                        1     Control CPP (-)                                                                            142.8     3.38   53.3                                      2     0.3% CPP Added                                                                             148.3     3.30   54.7                                      ______________________________________                                    

Example 3

A commercial layer feed ("CI Hispec", trade name, C. Itoh Feed MillsCo., Ltd.) was blended with CPP so as to become 0.03 wt. %, 0.10 wt. %,0.30 wt. % or 1.00 wt. %.

100 adult chicknes of 481 days old were divided into 5 groups eachcomposed of 20 chickens. Each group was fed with one of the above feedsor the original commercial feed not blended wtih CPP, and bred for 15days. The eggshell strength of the eggs produced in the last 3 days ofthe test period was measured, and compared with that produced in thepreliminary stage immediately before the test period.

The results are shown in Table 3.

                  TABLE 3                                                         ______________________________________                                        CPP   Eggshell Strength                                                       Group Content (%)                                                                              Preliminary stage (CPP.sub.(-))                                                                Test Period                                 ______________________________________                                        1     --         3.36 (100)       2.94 (87.5)                                 2     0.03       3.25 (100)       3.22 (99.1)                                 3     0.10       3.33 (100)        3.33 (100.0)                               4     0.30       3.12 (100)       2.91 (93.3)                                 5     1.00       3.25 (100)       3.07 (94.5)                                 ______________________________________                                    

The number in parenthesis is the ratio to the eggshell strength at thepreliminary stage (100).

We claim:
 1. A method for feeding of fowl comprising feeding chicks ofup to ten weeks of age with a calcium increasing effective amount of afeed composition consisting essentially of:(a) 12% to 25% by weightcrude protein, (b) 3% to 10% by weight crude fat, (c) 1% to 4.5% byweight calcium, and (d) 0.01% to 1% by weight of a composition obtainedby digesting casein with a proteolytic enzyme and concentrating anddrying the entire casein phosphopeptide containing digestive product. 2.The method of claim 1 wherein the composition obtained in step d)consists essentially of casein phosphopeptide having a peptide chain of##STR2## and a molecular weight of less than 10,000.
 3. The method ofclaim 1 wherein the composition obtained in step d) consists essentiallyof casein phosphopeptide having the peptide chain portion of Asp⁴³ toLys⁷⁹ of α-casein or the peptide chain portion of N-terminal to Arg²⁵ ofβ-casein.
 4. The method of claim 1 wherein the proteolytic enzyme ispepsin or trypsin.
 5. A method for feeding fowls which comprises feedingchicks of up to ten weeks old with a calcium increasing effective amountof a feed composition consisting essentially of:(a) 12% to 25% by weightcrude protein, (b) 3% to 10% by weight crude fat, (c) 1% to 4.5% byweight calcium, and (d) 0.01% to 3.00% by weight of caseinphosphopeptide having three active sites to bind calcium, which caseinphosphopeptide consists essentially of the entire digestion product ofcasein obtained by digesting casein with a proteolytic enzyme andconcentrating and drying the digestion product.